Herbs, perennial. Taproots often stout. Stems prostrate, much-branched proximally, terete to angular. Leaves opposite, not connate, connected by thickened margins from which stipules arise, sessile; stipules 2 per node, silvery, lanceolate to ovate, margins entire to irregularly fimbriate, apex 2-lobed; blade prominently 1-veined, needlelike, not succulent, apex spinose. Inflorescences axillary, 1-3-flowered clusters; bracts paired, resembling stipules, smaller. Flowers sessile; hypanthium cup-shaped, not abruptly expanded distally; sepals 5, distinct, olive-green, oblong to obovate, 1.2-2.8 mm (excluding awns), indurate, herbaceous, margins whitish, scarious, apex spinose, prominently hooded, awned, hoods projecting inward and enclosing developing fruit, awns arising from near apex, widely divergent, very stout, spinose, 3 awns and associated sepals well developed, alternating with 2 reduced sepals; nectaries not apparent; stamens 3-5; filaments distinct to base; staminodes 5, adnate basally with alternating filaments, ovate-triangular, apex acuminate; styles 2, distinct, subcapitate, 0.2 mm, glabrous proximally; stigmas 2, subterminal, obscurely papillate (50×). Utricles ellipsoid to cylindric, teeth absent, indehiscent. Seeds tan with red spot at hilum, narrowly ovate, not compressed, smooth, marginal wing absent, appendage absent; embryo peripheral, straight to slightly curved.
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